1. Field of the Invention
This invention relates in general to pipe clamps, and in particular to a pipe clamp with a slotted mounting bracket, used to affix electrical junction boxes and electrical device boxes to pipes.
2. Description of Related Art
In the electrical industry there exists requirements to affix electrical junction boxes and electrical device boxes to pipes to support the box. The National Electric Code requires that electrical junction boxes, and electrical device boxes be affixed both rigidly and securely. This requires that the method of attachment will hold the required weight, will not twist or move; and is held in alignment and position. To accomplish the rigid component as required by the National Electric Code, electric boxes are usually welded to a pipe; or attached with two screws, by drilling and tapping the pipe.
These two methods of attachment require additional tools, materials and skills for attachment. These additional tools, materials, and trades increase the construction time, and costs, by complicating the methods and mechanisms used for attachment. The following information is presented to give the reader an understanding and appreciation of the current methods, mechanisms and problems used in attaching devices of this nature to a pipe.
To weld an electrical junction box to a pipe, the electrician, must incorporate a welder by trade, a welding machine, and welding materials. The weldor, welds the back of the junction box to the pipe surface. The heat of the welding process removes the galvanized coating off the electrical box. The galvanized coating was applied to the box for the purpose of corrosion protection. The box must then be primed and painted to replenish its corrosion protection as required by the National Electric Code construction specifications. The welding process also creates rough surfaces inside the back of the box. These rough surfaces may cause a ground fault; if the conductors inside the box rub against them. This is not allowable according to the National Electrical Code. Once the boxes are welded to the pipe, they are considered a permanent fixture, and cannot be removed unless they are cut off with a cutting torch, or beat off with a hammer. Both of these methods destroy the box.
To use the method of drilling and tapping to affix an electrical junction box or device box to a pipe, an electrician uses the pre-punched holes located in the back of all junction, and device boxes, as a template to mark the hole locations on the pipe. Once the pipe is marked, two holes are drilled and tapped into the surface of the pipe. It is difficult to correctly center, mark, and align the back of the box, which is flat, against the round surface of the pipe. The end result of this method is normally a misaligned, or off center attachment of the box. Also, if the box is out of alignment, it can only be corrected by enlarging one hole, and retapping the hole to a larger size screw. This means the box will have to be redrilled from the standard punchsize, to the larger size screw. This method allows the boxes to be removed without damage to the box; but to re-position the box requires additional work, tools, and materials, for proper attachment.
Requirements also exist to be able to attach an electrical box in hazardous areas, where flammable, or electrical spark producing equipment are not allowed. In this case, the fire department must be contacted and may require that the area be evacuated, vented, or the area shut down for safety, and to meet electrical and safety codes.
There is therefore a need to provide a method and mechanism that will attach an electrical junction or device box to a pipe, which provides the following objects, advantages, and features for attachment:
(a) Requires only one mechanism for the support of the box; PA0 (b) Requires only the means of screws, nuts and a screwdriver for attachment of the clamp to the pipe, and attachment of devices to the clamp; PA0 (c) Provides the method to quickly, easily and correctly attach the box, with the first attempt, without having to reweld, or redrill and retap; PA0 (d) Provides a secure and rigid support for the box; PA0 (e) Provides a method to quickly, easily and safely attach the box in hazardous areas, without having to evacuate or shut down the area; PA0 (f) Provide a method to quickly and easily unfasten, and reattach the box; PA0 (g) Provide a method to easily adjust and center the box on the pipe; PA0 (h) Eliminate the use of welding, drilling and tapping, and the tools, materials, damage and increased costs associated with these methods for attachment. PA0 (a) Requires only one mechanism for attachment of the electrical box; PA0 (b) Requires only the means of screws, nuts and a screwdriver for attachment of the clamp to the pipe, and attachment of the box to the clamp; PA0 (c) Provides a method to quickly, easily and correctly attach the box, with the first attempt; PA0 (d) Accepts the sliding of screws and nuts into the edge of the mounting slot for quick and easy attachment; PA0 (e) Allows for attachment of screw and nut assemblies after they have been inserted into the back of the box, and after the nut has been screwed on the end of the screw; PA0 (f) Allows for easy positioning, centering, alignment of the box, by loosening the screws; PA0 (g) Accepts any screw size, type, or thread within design range; PA0 (h) Accepts any linear screw hole pattern on the back of a box, within design range; PA0 (i) Provides a rigid and secure attachment as required by National Electrical Codes; PA0 (j) Allows for unfastening or refastening of boxes, without damaging the box; PA0 (k) Allows for easy adjustment and centering of the box; PA0 (l) A method that does not require any welding, materials or tools for attachment; PA0 (m) A method that does not destroy the galvanized coating of the box during attachment as with welding; PA0 (n) A method that does not produce sharp edges inside the back of the box, as with welding, and break the National Electrical Codes; PA0 (o) Does not produce the debris due to welding, drilling or tapping; PA0 (p) Does not require re-welding due to misalignment; PA0 (q) Does not require any drilling or tapping, or the materials and tools required with these skills; PA0 (r) Does not require any redrilling to misalignment; PA0 (s) Allows for easy, quick and safe attachment in areas of a hazardous nature where spark producing tools and equipment are prohibited.
These objects as well as other objects, advantages and features will become apparent from the discussion that follows, and are achieved according to the present invention of an Electrical Junction Box Support Clamp.